1. Field of the Invention
This invention relates to a shock-absorbing device, more particularly to a durable shock-absorbing device.
2. Description of the Related Art
Referring to FIG. 1, a conventional shock-absorbing device is shown to comprise a length of coiled spring 13 that is adapted to be connected to a bicycle frame 10. The ends of the coiled spring 13 are connected pivotally to two pivot lugs 11, 12 that are mounted on the bicycle frame 10. When shock is transmitted from a rear bicycle wheel 14 to the bicycle frame 10, the coiled spring 13 is deformed longitudinally in order to retard the vibration of the rear bicycle wheel 14.
Referring to FIG. 2, another conventional shock-absorbing device is shown to include a coiled spring 21 that is adapted to be disposed between a seat 20 and a seat tube 22 of a bicycle. When shock is transmitted from the seat 20 to the seat tube 22, the coiled spring 21 is deformed in order to retard the vibration of the seat 20.
Since the conventional shock-absorbing devices are made of metal and are exposed to air, the weather resistance and the durability of the conventional shock-absorbing devices are relatively poor.